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Ritu R Gill
ES09 - How I Do It - Real World Issues in the Diagnosis and Treatment of Metastatic NSCLC (ID 12)
- Event: WCLC 2019
- Type: Educational Session
- Track: Treatment in the Real World - Support, Survivorship, Systems Research
- Presentations: 1
- Now Available
- Moderators:Margarida Dias, David Dawe, Carlos Cabrera
- Coordinates: 9/08/2019, 13:30 - 15:00, Tokyo (1982)
ES09.02 - How I Report Imaging for Assessment of Responses to Targeted Therapies vs. Immune Checkpoint Inhibitors vs. Chemotherapy (Now Available) (ID 3200)
13:30 - 15:00 | Presenting Author(s): Ritu R Gill
How I Report Imaging for Assessment of Responses to Targeted Therapies vs. Immune Checkpoint Inhibitors vs. Chemotherapy
Response assessment is an integral part of radiological reporting in tumor imaging. Our daily workflow includes diagnostic evalaution, determining resectability and response assessment. The radiology template and format is determined by the indication of the exam, and the clinical report may not include detail of all the lesions, but is a synopsis of the findings and an overview of the disease state and longitudinal change on the current therapy. In general our clinical reports do not have details related to detailed response categories and criteria. Response assessment is reported through a separate portal, which is generally overseen by the clinical trials office.
Response to therapy is the primary endpoint in most Phase I and II clinical trials. The response criteria to be used and primary and secondary endpoints are detailed in the study protocols based on the type of drug being used. In the era of precision medicine, the traditional response criteria have been evaluated and modified to assess response in targeted and immune therapies. The immune response criteria were developed to follow delayed healing and pseudoprogression. This presentation will discuss details on how I assess response in the context of chemotherapy, targeted therapy and immunotherapy.
Assessment of response to chemotherapy was performed using RECIST initially published in 2000 and revised in 2009(1,2). In the current practice RECIST 1.1 is used unless specified by the study protocol. The study protocol will detail the modality technique, duration and reporting criteria. In general the detailed protocol will prove information on the modality of choice. In traditional chemotherapy, the effect of cytotoxic drugs results in gross rumor reduction in most cases. Most trials require more than I independent reviewers, and may have an onsite review and a central review for confirmation of response.
Targeted therapies require matching the right gene mutation to the right pharmaceutical agent, which improves the efficacy and the effectiveness of therapy. Response assessment is on similar lines as chemotherapy. However, response beyond RECIST progression may be allowed on investigator discretion, if the tumor is progressing very slowly and the subject is asymptomatic. In patients with EGFR-mutant NSCLC treated with EGFRTKI, continued EGFR-TKI therapy may be indicated in those patients with progressive disease as these tumors grow slowly over many months and some tumor cells may remain sensitive to EGFR-TKI (3). Erlotinib and crizotinib are commonly continued beyond RECIST progression, because of an initial dramatic response followed by slow progression over many months in relatively asymptomatic patients.
Immunotherapy trials are assessed using immune response criteria (iRECIST), the main difference between iRECIST and RECIST, is that the patients are allowed to continue on therapy once disease progresses (PD) for another cycle is continued PD, to ensure it is not pseudoprogression(4). Response assessment in immune therapy trials, allows an extra cycle at 4 to 5 weeks after progression is documented before a decision is made to change therapy. Progression is confirmed at the following cycle or with pathology confirmation.
Additional criteria from PETCT and MRI and CT using volumetric assessment is used in the research arena, but not yet used universally for clinical trials. Modified RECIST(5) is more appropriate for pleural tumors as it improves reproducibility of measurements across reviewers and time points. Volumetric assessment is thought to more representative of the morphological changes but definite cut offs as surrogate of the response need validation(6). MRI can assess both size and cellularity and function and hence MR based response assessment derived from apparent diffusion coefficient and pharmacokinetic parameters such as area under the curve, permeability coefficient and elimination coefficient can provide anatomical and functional response to therapy(7,8).
It is vital to make a note of any atypical findings and also to recognize adverse events related to the drug and help with timely management. The presentation will detail how I assess response in the real world with case specific examples and illustration of some atypical responses and lesions that can mimic progression.
1. Therasse P, Arbuck SG, Eisenhauer EA, Wanders J, Kaplan RS, Rubinstein L, et al. New Guidelines to Evaluate the Response to Treatment. J Natl Cancer Inst. 2000;92(3):205–16.
2. Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D, Ford R, et al. New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1). Eur J Cancer. 2009;45(2):228–47.
3. Mok TSK. Living with imperfection. Journal of Clinical Oncology. 2010;28(2):191–2.
4. Seymour L, Bogaerts J, Perrone A, Ford R, Schwartz LH, Mandrekar S, et al. iRECIST: guidelines for response criteria for use in trials testing immunotherapeutics. Vol. 18, The Lancet Oncology. 2017. p. e143–52.
5. Byrne MJ, Nowak AK. Modified RECIST criteria for assessment of response in malignant pleural mesothelioma. Ann Oncol. 2004;15(2):257–60.
6. Frauenfelder T, Tutic M, Weder W, Götti RP, Stahel RA, Seifert B, et al. Volumetry: An alternative to assess therapy response for malignant pleural mesothelioma? Eur Respir J. 2011;38(1):162–8.
7. Ohno Y, Koyama H, Onishi Y, Takenaka D, Nogami M, Yoshikawa T, et al. Non–Small Cell Lung Cancer: Whole-Body MR Examination for M-Stage Assessment—Utility for Whole-Body Diffusion-weighted Imaging Compared with Integrated FDG PET/CT. Radiology. 2008;248(2):643–54.
8. Giesel FL, Choyke PL, Mehndiratta A, Zechmann CM, von Tengg-Kobligk H, Kayser K, et al. Pharmacokinetic analysis of malignant pleural mesothelioma-initial results of tumor microcirculation and its correlation to microvessel density (CD-34). Acad Radiol [Internet]. 2008 May [cited 2014 Oct 2];15(5):563–70.
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